Of a subscriber identity module by several mobile communication devices

ABSTRACT

A method is provided for achieving an external access of a first mobile communication terminal (ME) to a Subscriber Identity Module (SIM) of a second mobile communication terminal (ME). A logical interface between the first and the second mobile communication terminal is defined by which a logical autonomous communication between the first and second mobile communication terminal is established. Also provided is an arrangement of at least one first and one second mobile communication terminal (ME), in which a logical interface is defined by which the first mobile communication terminal has access to a SIM of the second mobile communication terminal.

BACKGROUND OF THE INVENTION

The present invention relates to a method for implementing access by afirst mobile communication appliance (mobile equipment ME) to asubscriber identity module (SIM) or universal subscriber identity module(USIM) in a second mobile communication appliance (ME). In this case,the mobile communication appliance may be, by way of example, a mobilephone, a car telephone, a modem, a radio modem or a wireless module.

A SIM card in a mobile communication appliance is used to store data forauthentication in GSM, GPRS or UMTS mobile radio networks and otheruser-related information. In addition, the SIM is used to allocate thenetwork resources used by a mobile communication appliance to a user andhence to an account.

A SIM card includes a processor which, inter alia, looks after analgorithm for secure authentication in the network. This processor islocated on a card, a “smart card,” which is inserted into a SIM cardreader. This reader is, in turn, integrated in a mobile communicationnetwork.

As such, any mobile communication appliance which wants to register andauthenticate itself in a GSM/UMTS mobile radio network needs to have aSIM. Since the account to be identified is associated with one user,however, the use of a number of mobile communication appliances by oneuser is possible only by virtue of different logical users (i.e.,different mobile communication appliances), being allocated to oneaccount on the books; for example, using a “twin card” from D1.

To date, it has not been possible for one user with different mobilecommunication appliances to register in a GSM mobile radio network usingone identity; i.e., using one SIM.

With the expansion of the possible mobile services which can be usedwith a mobile communication appliance, the demands on the mobilecommunication appliances are increasing considerably. It follows fromthis that a user uses various mobile services using a number of mobilecommunication appliances which are specifically for the respectiveservice.

To allow the user to access the GSM/UMTS mobile radio network usingvarious mobile communication appliances, it is necessary for the user tobe able to register with the GSM/UMTS mobile radio network using eachmobile communication appliance.

The present invention is directed toward a method and a system includingmobile communication appliances which a user can use to register in aGSM/UMTS mobile radio network as quickly and easily as possible using anumber of mobile communication appliances.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a method for implementingexternal access by a first mobile communication appliance (ME) to asubscriber identity module (SIM) in a second mobile communicationappliance (ME), where a logical interface between the first and secondmobile communication appliances is defined which permits logicalautonomous communication between the first and second mobilecommunication appliances.

To date, every mobile communication appliance has had to incorporate aSIM for identifying a user or subscriber. The SIM is part of a mobilecommunication appliance. To allocate a number of SIM cards (i.e., inprinciple, a number of mobile communication appliances), to a user orhis/her account, some mobile radio providers have “twin cards.” Thesecards are used, by way of example, to settle accounts for two mobilecommunication appliances belonging to a user together.

This solution has drawbacks, however. Since two mobile communicationappliances with separate SIM cards are addressed by just one telephonenumber, the corresponding network does not know which appliance is to beused for signaling incoming calls. Additional coordination complexity bythe network or user is required in order to identify the activecommunication appliance; e.g., use of the last mobile communicationappliance registered in the network.

There is no opportunity for automatic changeover between the mobilecommunication appliances.

In addition, a user is not able to use one mobile communicationappliance to access the SIM in another mobile communication appliance.As such, services such as a telephone book are available to him/her onlyon the mobile communication appliance which is connected directly to theSIM card reader, for example.

Another drawback is that each mobile communication appliance needs tocontain a separate SIM with a card reader. This is very expensive.

The present invention now provides a method which allows a mobilecommunication appliance to access the subscriber identity module (SIM)in another mobile communication appliance. In this case, the accesstakes place via an external logical interface. If a mobile communicationappliance does not have a SIM available, the present invention allows aninventively defined logical interface to be used to access the data onthe SIM card in another mobile communication appliance.

In one embodiment of the inventive method, the first and second mobilecommunication appliances contain a respective adaptation layer whichadapts logical communication between the first and second mobilecommunication appliances to the logical interface. As such, a SIMservice manager is provided which controls the access to the externalSIM.

In addition, the logical interface defined is preferably anAT-command-based interface. The logical communication is independent ofthe underlying transmission technology.

In a further embodiment of the inventive method, the logical interfaceuses a client/server architecture. The adaptation layer provided inaccordance with the present invention is part of the aforementioned SIMservice manager. The adaptation layer adapts the logical communicationbetween a client and a server to the logical, preferablyAT-command-based interface. In this case, the mobile communicationappliance without a SIM takes on the role of the client, whereas themobile communication appliance with the SIM provides the “SIM Service”service and thus adopts the role of the server. The server, or moreprecisely the SIM access server, allows another mobile communicationappliance to access the data on a SIM card using an external logicalinterface. The server may be, by way of example, a mobile telephonewhich has an integrated SIM card. A radio or cable link can be used bythe mobile telephone to allow, as a server, other mobile communicationappliances to access his/her SIM card.

The client, or more precisely the SIM access client, uses a server's SIMcard via an appliance connection to such server using an externallogical interface. The SIM access client may be, by way of example, aGSM/GPRS module which is mounted in a car. This module is intended toalign, by way of example, the communication via a mobile radio networkwith the specific environment.

The client sends a request, for example, to the server. This ispreferably done by sending the request to the server as an AT commandvia an external AT-command-based interface. The server responds with aResponse information item, which is sent to the client; likewise,preferably as an AT command. The server can report events even withoutprior requesting by the client using “unsolicited result codes” (URCs).

One great advantage of the present invention is the use of an AT commandinterface to implement external access to a SIM; i.e., to permit SIMsharing. In this case, a mobile communication appliance (which then actsas a server) provides another mobile communication appliance (which isthen a client and wishes to use a service) with a SIM which makes itpossible to use the service.

In a further embodiment of the inventive method, the logical interfaceuses RS-232, USB, Bluetooth, Wireless-LAN (WLAN) or Ultra-Wide-Band(UWB) as transmission technology.

The logical interface's independence of the transmission technologyresults in the advantage, by way of example, that the SIM sharing easilycan be transferred to different instances of application.

The present invention also relates to a corresponding system includingat least one first and a second mobile communication appliance (ME),where a logical interface is defined which provides the first mobilecommunication appliance with access to a SIM in the second mobilecommunication appliance.

In this case, as already mentioned, the logical interface is preferablyan AT-command-based interface.

In one embodiment of the inventive system, the first and second mobilecommunication appliances contain a respective adaptation layer whichadapts logical communication between the first and second mobilecommunication appliances to the logical interface.

Preferably, the logical interface can use RS-232, USB, Bluetooth,Wireless-LAN (WLAN) or Ultra-Wide-Band (UWB) as transmission technology.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the Figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a schematic illustration of an embodiment of the flow ofthe method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows one possible application of the inventive method in a motorvehicle 1. The motor vehicle (KFZ) 1 contains a permanently installedmobile communication appliance ME 2 in the form of a GSM/GPRScommunication module which is optimized to the demands, inter aliarelating to vibration and temperature resistance, on the environment.The tasks of the ME 2 are, inter alia, accident emergency call,transmission of navigation data, access to vehicle data for servicepurposes and telemetry, for example.

The permanently installed ME 2 uses its antenna 4 arranged outside ofthe passenger compartment 3 to provide wireless access to the mobileradio network. The ME 2 does not have its own SIM card, however, and istherefore configured as a client. If a user with a mobile telephone ME 5now gets into the passenger compartment 3, he can put the ME 5 into adevice 6 provided for such purpose. This device provides a data link,such as a serial data cable, to the fitted GSM/GPRS module ME 2. The ME5 is configured as a server and makes its SIM available to the fitted ME2. The ME 2 thus undertakes the communication with the mobile radionetwork after the ME 5 has turned off its GSM/GPRS air interface.Accordingly, the user is provided with a communication system which isoptimized to this environment.

Although the present invention has been described with reference tospecific embodiments, those of skill in the art will recognize thatchanges may be made thereto without departing from the spirit and scopeof the present invention as set forth in the hereafter appended claims.

1-8. (canceled)
 9. A method for implementing external access by a firstmobile communication appliance to a subscriber identity module in asecond mobile communication appliance, the method comprising: defining alogical AT-command-based interface between the first and second mobilecommunication appliances; and permitting, via the logicalAT-command-based interface, logical autonomous communication between thefirst and second mobile communication appliances.
 10. A method forimplementing external access by a first mobile communication applianceto a subscriber identity module in a second mobile communicationappliance as claimed in claim 9, wherein the first and second mobilecommunication appliances contain a respective adaptation layer whichadapts logical communication between the first and second mobilecommunication appliances to the logical AT-command-based interface. 11.A method for implementing external access by a first mobilecommunication appliance to a subscriber identity module in a secondmobile communication appliance as claimed in claim 9, wherein thelogical AT-command-based interface uses a client/server architecture.12. A method for implementing external access by a first mobilecommunication appliance to a subscriber identity module in a secondmobile communication appliance as claimed in claim 9, wherein thelogical AT-command-based interface is used independently of atransmission technology being used, the logical AT-command-basedinterface using one of RS-232, USB, Bluetooth, Wireless-LAN andUltra-Wide-Band.
 13. A system for implementing external access by afirst mobile communication appliance to a subscriber identity module ina second mobile communication appliance, comprising: a first mobilecommunication appliance; a second mobile communication appliance; and alogical AT-command-based interface defined between the first and secondmobile communication appliances, wherein the logical AT-command-basedinterface provides the first mobile communication appliance with accessto a subscriber identity module in the second mobile communicationappliance.
 14. A system for implementing external access by a firstmobile communication appliance to a subscriber identity module in asecond mobile communication appliance as claimed in claim 13, whereinthe first and second mobile communication appliances contain arespective adaptation layer which adapts logical communication betweenthe first and second mobile communication appliances to the logicalAT-command-based interface.
 15. A system for implementing externalaccess by a first mobile communication appliance to a subscriberidentity module in a second mobile communication appliance as claimed inclaim 13, wherein the logical AT-command-based interface may use one ofRS-232, USB, Bluetooth, Wireless-LAN and Ultra-Wide-Band as transmissiontechnology.
 16. A system for implementing external access by a firstmobile communication appliance to a subscriber identity module in asecond mobile communication appliance as claimed in claim 13, wherein nosubscriber identity module is used in the first mobile communicationappliance.